Combination well bailer and swab

ABSTRACT

A combination well bailer and swab having a plunger slidably disposed in the body of the bailer and a swab cup supporting mandrel secured to the lower end of the bailer with an overload relief valve disposed below the swab cup. Ports are provided through the swab mandrel above the swab cup, communicating with the annulus exteriorly of the swab mandrel, with an upwardly opening flapper check valve between the ports and the plunger so that upon upward movement of the plunger the flapper valve is opened, drawing fluid interiorly of the body from above the swab cup, thereby drawing suspended sand and other foreign material into the body where it may be collected or expelled, and an undue accumulation of sand within the body will open the safety relief valve and dump same into the well below the swab cup.

United States Patent 1 Reynolds 1 June 19, 1973 COMBINATION WELL BAILERAND SWAB 2,785,756 3/1957 Reynolds 166/107 [76] Inventor: John M.Reynolds, 403 Monrovia L 0 Primary Exammer Dav1d H. Brown StreetShreveport a 71] 6 Attorney-Howard E. Moore and Gerald G. Grut- [22]Filed: Oct. 6, 1971 singer App]. No.: 187,007

Related US. Application Data [57] ABSTRACT A combination well bailer andswab having a plunger slidably disposed in the body of the bailer and aswab cup supporting mandrel secured to the lower end of the bailer withan overload relief valve disposed below the swab cup. Ports are providedthrough the swab mandrel above the swab cup, communicating with theannulus exteriorly of the swab mandrel, with an upwardly opening flappercheck valve between the ports and the plunger so that upon upwardmovement of the plunger the flapper valve is opened, drawing fluidinteriorly of the body from above the swab cup, thereby drawingsuspended sand and other foreign material into the body where it may becollected or expelled, and an undue accumulation of sand within the bodywill open the safety relief valve and dump same into the well below theswab cup.

9 Claims, 6 Drawing Figures PATENTEB 3.739.847

oo may:

9 INVENTOR V JOHN M. REYNOLDS A TTOR Y5 COMBINATION WELL BAILER AND SWAB1969, now US. Pat. No. 3,621,925 which issued Nov.

BACKGROUND OF THE INVENTION Hydraulic bailers either with or withoutpercussion tools attached thereto are often employed to remove sand,cement,metal objects, bridge plugs, packers and drill bits from the wellbore. Bailers of the type disclosed in US. Pat. Nos. 3,177,956, and3,168,152, and in my Patent application Ser. No. 861,078 now US. Pat.No. 3,621,925, are employed for a variety of purposes in the drilling,completion, extension and reworking of wells. However, such tools havedefinite limitations in that in some instances they become impacted withsand to an extent that they cannot be retrieved from the well. Thus,their capacity for removal of sand on each trip is limited.

Swab equipment heretofore employed for removal of fluid from wells hasdefinite limitations, particularly in wells having an excessive amountof sand suspended in the fluid therein.

There have been two general types of swab cups employed, to-wit; (1) thereinforced types having reinforcing wires or other supports embedded inthe wall thereof to strengthen same and prevent same from turning overand dumping fluid, and (2) so-called sand cups which have unreinforcedflexible flanges thereon which when they get under an excessive load ofsand will turn over or rupture to dump the sand and allow retrieval ofthe swab from the well. The reinforced type is objectionable for use insand-laden wells because sand becomes impacted above it so that itsticks in the well. The unreinforced type is objectionable because itwill not lift as great a load of fluid from the well on each run as thereinforced type, but same is necessarily used in wells having an excessamount of suspended sand in the oil to prevent sticking.

SUMMARY OF INVENTION This invention is addressed to a combination wellbailer and swab cup which utilizes the function of the well bailerplunger to draw suspended sand and fluid from above a swab cup suspendedtherebelow into the barrel of the bailer and to deposit sand inside themandrel where an excess amount thereof will open a relief check valve toallow same to be deposited in the well below the swab cup, to therebyprevent an excess amount of sand from accumulating above the swab cup toan extent that would cause same to stick and become lodged in the well.

Such a device allows the use of reinforced swab cups in wells havingexcess amount of suspended sand therein with safety, and thereby permitsthe removal of a greater amount of fluid from the well on each run intothe well.

It is desirable to employ a well bailer with a plunger of the typedisclosed in my co-pending application Ser. No. 861,078 which has spacedrings thereon with annular grooves in the outer surfaces thereof toreceive sand, said rings being enabled to wobble on the support thereforto permit solid particles which would tend to cause excessive wear onthe outer surface thereof to work past the ring; and having rigid finsor plates secured to the mandrel of the plunger to provide hydraulicdamping to minimize rotation of the plunger relative to the body of thebailer.

Normally when the bailer assembly strikes an obstruction or the bottomof the well bore the sudden release of tension on the cable supportingsame causes twisting of the cable and spinning of the piston rings inthe body of the bailer and a torque motion applied to the body of thebailer, thereby tending to cause the loosening of threads attaching thebody to the swab mandrel.

Provision is made in the combination well bailer and swab hereindescribed and claimed to compensate for such tendency to unthread theswab mandrel from the bailer body by the provision of radially arrangedslots or recesses in the head of the barrel which receive hydraulicforce caused by pressurized fluid in the barrel when the plunger ismoved upwardly therein to thereby tend to rotate the barrel withreference to the swab mandrel to tighten the threaded connectiontherebetween and prevent disengagement thereof.

It is therefore a primary object of the invention to provide acombination well bailer and swab which will permit the removal of agreater amount of sand laden fluid from the well with heavy duty swabcups without the danger of lodging or sticking the assembly in the well.

Another object of the invention is to provide a com bination well bailerand swab incorporating a plunger in the body which draws fluid from theannulus in the well above the swab cup and deposits same in the bodywhere it may be dumped by an overload relief valve below the swab cup toprevent the sticking of the swab by an excess amount of sand collectedthereabove.

Still another object of the invention is the provision of means inresponse to fluid pressure inside the plunger barrel to causetightening, of threads between the plunger barrel and the swab mandrelto prevent disengagement thereof while in use.

Other and further objects of the invention will become apparent byreferring to the detailed description and drawing annexed hereto.

DESCRIPTION OF DRAWING A drawing of a preferred embodiment of theinvention is annexed hereto so that the invention may be better and morefully understood, in which:

FIG. I is a partially sectionalized view of the bailer and swabcombination;

FIG. 11 is a cross sectional view taken along line II--Il of FIG. 1;

FIG. III is a cross sectional view taken along line III- -III of FIG. I;

FIG. IV is a cross sectional view taken along line lV-IV of FIG. I;

FIG. V is a cross sectional view taken along line VV of FIG. I; and

FIG. VI is a lower end view taken along the line VI-VI of FIG. I.

Numeral references are employed to indicate like parts throughout thevarious figures of the drawing.

DESCRIPTION OF A PREFERRED EMBODIMENT In the drawing the numeral 1generally designates a well bailer having a body comprising a hollowtubular barrel 2, the upper end of which is rigidly connected to a head4 as by welding 3, and having a cylindrical bore 6 extendinglongitudinally therethrough.

The upper tubular stem section 10 of a plunger assembly 8 is slidablydisposed through the bore of head 4. The head 4 has shoulders 12 and areduced section 14 at the upper end thereof with threads or teeth 16disposed thereabout to facilitate connecting a fishing tool (not shown)thereto to remove the bailer from a well bore, should it be necessary todo so.

Suitable lowering means, such as wire rope 18, is secured to the upperend of stem section of the plunger assembly 8 and extends upwardlythrough the well bore to suitable dispensing means such as the drum of awench (not shown).

A traveling valve cage 20 is secured to the lower end of stem section10, said valve cage having a curved shoulder portion 22 on the upper endthereof arranged to enter and engage the beveled lower end 24 of bore 6which extends through the head 4.

Valve cage 20 has apertures 26 extending through the walls thereof andthe lower end of the valve cage is threadedly connected at 28 to theupper end of a hollow tubular mandrel 30. Mandrel 30 has a passage 32extending longitudinally therethrough. A valve seat 34 is formed in theupper end of passage 32 and receives valve element 36 to p'event theflow of fluid downwardly through passage 32.

The mandrel 30 has rings 65 mounted thereon below the lower end of thetraveling valve cage 20. Rings 65 are rigid cylindrical elements havinga bore 66 extending therethrough. Referring to FIGS. 1 and III, itshould be noted that bore 66 through ring 65 is of larger diameter thanthe outside diameter of mandrel 30, thus providing clearance betweenmandrel 30 and ring 65.

Each ring 65 is restrained from axial movement along mandrel 30 byshoulders 68 and 69 which extend outwardly from mandrel 30 above andbelow each ring 65. Clearance is also provided between the lower edge ofupper shoulder 68 and the upper edge of ring 65 so as not to preventrocking motion of ring 65 relative to mandrel 30.

The outer circumference of each ring 65 has one or more annular grooves70 formed therein with lands or ridges 72 extending around the upper andlower edges of each groove 70.

The outside diameter of each land 72 is of smaller diameter than that ofbore 60 which extends through the barrel 2 of the body of the bailer.Provision of clearance between the outside edge of lands 72 and theinner wall 74 of bore 60 allows each ring 65 to tilt or wobble relativeto the inner wall 74 of the barrel 2 as the plunger assembly 8 movesvertically relative to the body portion of the bailer.

From the foregoing it should be readily apparent that the rigid rings 65are restrained from axial movement by shoulders 68 and 69 on mandrel 30of the plunger assembly 8 and that each ring 65 is free to rock and tiltas the plunger assembly 8 moves through the bore 60 of the body portionof the bailer to prevent wedging of solid materials between the outeredges of the piston 65 v and the wall 74.

Annular grooves 70 in the edges of each rigid ring 65 cause agitation offluid which flows through the clearance between the outer edges of lands72 and the inner wall 74 of barrel 2 to increase the vacuum formingcamandrel 30 between shoulders 68 and 69 and extend outwardly from saidmandrel between rigid rings 65. Fins 86 are fixedly secured to the lowerend of mandrel 30 below the lowermost ring 65.

Since check valve 52 in the swab barrel prevents the flow of fluiddownwardly through bore 60, fluid is normally present in said bore. Theweight of bailer 1 suspended from a long length of wire rope 18 causesthe wire rope to stretch, resulting in the exertion of a considerabletorque on plunger assembly 8 when the weight of the bailer is suddenlyremoved from wire rope 18 as the swab assembly therebelow strikes anobstruction in the well bore. Fins 80, 82, 84 and 86 on the travelingvalve cage 20 and the mandrel 30, respectively, provide hydraulicbraking action to reduce the tendency of plunger assembly 8 to spinrelative to the barrel 2 of the bailer body.

A tubular swab support mandrel 40 is threadedly attached by threads 41to barrel 2. Longitudinally spaced perforations 43 are provided throughthe wall of support 40 which cause communication between the bore 42 ofsupport 40 and the annulus between same and the surrounding casing orother pipe in the well.

An overload valve assembly is formed on the lower end of swab supportmandrel 40 which includes a partition having a valve passage 44therethrough with a seat 46 about the lower end thereof closed by avalve ball 47.

Valve ball 47 is urged against seat 46 by a spring 48 which is supportedby a ring 49 having passages 49a therethrough. The ring 49 is mounted onthe inner end of threaded stud 50 having a head 50a thereon. The stud 50threadedly extends through the lower end 102 of swab body so that byrotating the stud 50 the tension of spring 48 may be adjusted. The lowerend 102 is a web providing passages 51 through which sand may be dumpedwhen valve 47 opens.

A flapper valve 52 is pivotally mounted on hinge 52a and is arranged toseat upon partition 54 and close the passage 53 therethrough.

A flexible swab cup 55 which may take any form, either the reinforced orunreinforced type, is secured to the .mandrel 40 below perforations 43in a suitable manner such as by being seated on a support shoulder 56and held in place by a bushing 57 attached about the mandrel 40. Theswab cup 55 is arranged to expand under load imposed thereabove intosealing engagement with a surrounding pipe to trap fluid thereabove toremove same from the well.

As shown in FIG. V radially extending closed end passages 58 areprovided in the head 4; each said passage communicating at its inner endwith the annular passage 6 and being closed at its inner end 59.

The operation and function of the device hereinbefore described is asfollows:

The plunger 8 is moved up and down through barrel 2 until a maximum loadis drawn into loading chamber 60 through the perforations 43 and throughcheck valve 52 inside barrel 2.

As plunger 8 is moved vertically upward, fluid is drawn from the wellabove swab cup 55 through openings 43 to the inside of mandrel 40 andmoves upwardly through flapper valve 52.

Downward movement of plunger 8 causes fluid to move upwardly throughpassage 32 in plunger 8 and out through openings 26 above rings 65. Thenext upward stroke of plunger 8 draws more fluid through openings 43while moving fluid above rings 65 up wardly to discharge same aroundcable 18 through passage 6 in the head 4 at the upper end of the barrel2 into the annulus above swab cup 55. As the stem on the upper end ofplunger 8 moves upwardly in passage 6 the area through which fluid canflow is greatly reduced, resulting in a dampening action, increasingpressure above rings 65.

As best illustrated in FIG. V, pressurized fluid is directed frompassage 6 into passages 58 to impact the closed end 59 of each passage58 to exert a twisting action to barrel 2, tending to tighten thethreads 41 between barrel 2 and mandrel 40.

When the combined bailer and swab is being removed from the well byengagement of shoulders 22 and 24, sand above cup 55 may tend to stickthe tool in the well. If so, the plunger 8 may be reciprocated up anddown in barrel 2, drawing sand laden fluid through openings 43, and whena predetermined pressure (regulated by screw 50) is reached, valve 47will open to dump the sand through passage 51 into the well below cup55,allowing the cup and tool to be released and moved upwardly throughthe well without rupturing or damage to the swab cup.

Having described my invention I claim:

1. In a well tool, a tubular body having a plunger assembly slidablydisposed in the bore; one or more perforations provided through the wallof the body; a swab cup about the body below the perforations; anupwardly opening check valve in the body between the perforations andthe plunger; and a check valve below the swab cup arranged to opendownwardly when a predetermined pressure is imposed thereon.

2. In a combination plunger and well swab, a hollow barrel; a plunger inthe barrel; a head on the barrel having a central passage therethrough;a stem attached to the plunger movably extending through the passage,the stem being smaller in diameter than the central passage to providean annular restricted flow passage thereabout; a central passage throughthe plunger communicating with area above and below the plunger; an

upwardly opening check valve in the passage through the plunger; a swabassembly suspended to the barrel, said swab assembly including a tubularbody having perforations through the wall thereof; a swab cup disposedabout the body below the perforations; a downwardly opening check valvein the body below the swab cup; and passage means through the lower endof the body below the check valve.

3. The combination called for in claim 2 with the addition of anupwardly opening check valve in the body above the perforations.

4. The combinationcalled for in claim 2 with the addition of an enlargedhead on the plunger engageable with the lower end of the passage throughthe head to allow retrieval of the tool.

5. The combination called for in claim 2 wherein the barrel isthreadedly engaged with the swab body; and a plurality of radiallyarranged closed end passages in the head communicating with the centralpassage through the head arranged to receive pressure from the saidpassage when the plunger is raised to apply torque to the barrel totighten the threaded connection between the barrel and the body.

6. In a well tool, a tubular body having a plunger assembly slidablydisposed in the bore; a head on the upper end of the body, said headhaving a passage therethrough; a stern on the plunger assembly movablevertically in said passage, the stem being smaller in diameter than thepassage to provide an annular restricted flow passage thereabout; one ormore perforations provided through the wall of the body; a swab cupabout the body below the perforations; and a check valve below the swabcup arranged to open downwardly when a predetermined pressure is imposedthereupon.

7. The combination called for in claim 6 with the addition of a pair ofradially disposed closed end passages in the inner wall of the headcommunicating with the passage through the head arranged to receivefluid pressure from said restricted passage when the plunger is movedupwardly to impart a rotative motion to the body.

8. The combination called for in claim 6 with the addition of anenlarged head on the plunger below the stem arranged to engage thepassage to allow retrieval of the assembly from the well by a cableattached to the stem.

9. In a well tool, a tubular body having a plunger assembly slidablydisposed in the bore, said plunger having a passage therethrough toallow communication between areas in the body above and below theplunger; an upwardly opening check valve in the passage to control flowtherethrough; one or more perforations provided through the wall of thebody; a swab cup about the body below the perforations; and a checkvalve below the swab cup arranged to open downwardly when apredetermined pressure is. imposed thereupon. :0: a:

1. In a well tool, a tubular body having a plunger assembly slidablydisposed in the bore; one or more perforations provided Through the wallof the body; a swab cup about the body below the perforations; anupwardly opening check valve in the body between the perforations andthe plunger; and a check valve below the swab cup arranged to opendownwardly when a predetermined pressure is imposed thereon.
 2. In acombination plunger and well swab, a hollow barrel; a plunger in thebarrel; a head on the barrel having a central passage therethrough; astem attached to the plunger movably extending through the passage, thestem being smaller in diameter than the central passage to provide anannular restricted flow passage thereabout; a central passage throughthe plunger communicating with area above and below the plunger; anupwardly opening check valve in the passage through the plunger; a swabassembly suspended to the barrel, said swab assembly including a tubularbody having perforations through the wall thereof; a swab cup disposedabout the body below the perforations; a downwardly opening check valvein the body below the swab cup; and passage means through the lower endof the body below the check valve.
 3. The combination called for inclaim 2 with the addition of an upwardly opening check valve in the bodyabove the perforations.
 4. The combination called for in claim 2 withthe addition of an enlarged head on the plunger engageable with thelower end of the passage through the head to allow retrieval of thetool.
 5. The combination called for in claim 2 wherein the barrel isthreadedly engaged with the swab body; and a plurality of radiallyarranged closed end passages in the head communicating with the centralpassage through the head arranged to receive pressure from the saidpassage when the plunger is raised to apply torque to the barrel totighten the threaded connection between the barrel and the body.
 6. In awell tool, a tubular body having a plunger assembly slidably disposed inthe bore; a head on the upper end of the body, said head having apassage therethrough; a stem on the plunger assembly movable verticallyin said passage, the stem being smaller in diameter than the passage toprovide an annular restricted flow passage thereabout; one or moreperforations provided through the wall of the body; a swab cup about thebody below the perforations; and a check valve below the swab cuparranged to open downwardly when a predetermined pressure is imposedthereupon.
 7. The combination called for in claim 6 with the addition ofa pair of radially disposed closed end passages in the inner wall of thehead communicating with the passage through the head arranged to receivefluid pressure from said restricted passage when the plunger is movedupwardly to impart a rotative motion to the body.
 8. The combinationcalled for in claim 6 with the addition of an enlarged head on theplunger below the stem arranged to engage the passage to allow retrievalof the assembly from the well by a cable attached to the stem.
 9. In awell tool, a tubular body having a plunger assembly slidably disposed inthe bore, said plunger having a passage therethrough to allowcommunication between areas in the body above and below the plunger; anupwardly opening check valve in the passage to control flowtherethrough; one or more perforations provided through the wall of thebody; a swab cup about the body below the perforations; and a checkvalve below the swab cup arranged to open downwardly when apredetermined pressure is imposed thereupon.